Project B3 of the Cluster of Excellence Climate, Climatic Change, and Society (CliCCS) investigates interactions between climate change and insecurity dynamics. How do societies prepare for and respond to increasingly complex climate-security interactions? We examine scenario building as a social technology used by different societal and security communities to prepare for and act upon climate-security projections and related risks. The project asks how these adaptation and mitigation strategies can be oriented not only towards increased conflict, but also towards new forms of cooperation in the face of transnational risks and complex crises.